Heat sink

ABSTRACT

A heat sink adapter for cooling an electronic component includes a lower plate, an upper plate, an upper fin set and a lower fin set respectively fixed on the upper plate and the lower plate, and a plurality of heat pipes sandwiched between the upper plate and the lower plate. The lower plate includes a panel contacting the heat pipes, two sidewalls extending upwardly from the panel and separated from the heat pipes, and two flanges extending oppositely from the two sidewalls and soldered on the upper plate. The heat pipes are juxtaposed with each other at a central position thereof, and partially spaced from each other at two opposite end positions thereof.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a heat sink, and more particularly to a heat sink incorporating heat pipes for enhancing a heat dissipating efficiency thereof.

2. Description of Related Art

The central processing unit (CPU) mounted on the motherboard in a computer is the center of operations of the computer. During the operations of the computer, the CPU produces heat. The heat must be quickly carried away from the CPU during the operations of the computer. Accordingly, a heat sink is used to remove the heat from the CPU.

Conventionally, a heat sink includes a metal base contacting with the CPU to absorb heat therefrom, and a plurality of fins extending from the base to dissipate the heat to an ambient. In order to increase a heat dissipating efficiency, heat pipes are often embedded into the metal base to transfer the heat from the metal base to the fins more rapidly.

In most of the heat sinks, the heat pipes are accommodated in grooves which are defined in the metal base. However, the process to form the grooves in the metal base is costly since it needs a hard machine work. Furthermore, in order to receive the heat pipes therein substantially, the metal base should be made to have a thickness larger than diameters of the grooves, whereby a material cost of the metal base is increased.

What is needed, therefore, is a heat dissipating device which can overcome the above-mentioned disadvantages.

SUMMARY OF THE INVENTION

A heat sink adapter for cooling an electronic component includes a lower plate, a planar upper plate, an upper fin set and a lower fin set respectively fixed on the upper plate and the lower plate, and a plurality of heat pipes sandwiched between the upper plate and the lower plate. The lower plate includes a planar panel contacting the heat pipes, two sidewalls extending upwardly from the panel and separated from the heat pipes, and two flanges extending oppositely from the two sidewalls and soldered on the upper plate. The heat pipes are juxtaposed with each other at a central position thereof, and partially spaced from each other at two opposite end positions thereof. Compared with conventional heat sink that forms grooves on a base to embed heat pipes therein, the heat sink of the present invention does not need forming grooves in the lower plate, whereby a material cost and a machine work are reduced and avoided, respectively.

Other advantages and novel features of the present invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings, in which:

BRIEF DESCRIPTION OF THE DRAWINGS

Many aspects of the present apparatus can be better understood with reference to the following drawings. The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the present apparatus. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views.

FIG. 1 is an assembled, isometric view of a heat sink in accordance with a preferred embodiment of the present invention;

FIG. 2 is an exploded view of FIG. 1;

FIG. 3 is an enlarged view of heat pipes of the heat sink of FIG. 2 from another aspect;

FIG. 4 is an inverted view of FIG. 1; and

FIG. 5 is a front view of FIG. 1.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIGS. 1 and 2, a heat sink 10 in accordance with a preferred embodiment of the present invention is for being mounted on an electronic component (not shown) to dissipate heat therefrom. The heat sink 10 comprises a lower plate 20, an upper plate 30, a plurality of heat pipes 60 sandwiched between the lower plate 20 and the upper plate 30, and an upper fin set 40 and a lower fin set 50 attached on the upper plate 30 and the lower plate 20, respectively.

Also referring to FIG. 4, the lower plate 20 is made by bending a metal plate, it comprises a rectangular and planar panel 22, a pair of sidewalls 24 extending upwardly and perpendicularly from two opposite lateral sides of the panel 22, and a pair of flanges 26 formed horizontally and oppositely from tops of the pair of sidewalls 24, respectively. A square area of the panel 22 is stamped downwardly to form a protrusion 220 (shown in FIG. 4) projecting beyond a bottom face the panel 22, and a cavity 222 located corresponding to the protrusion 220 and beneath a top face of the panel 22. The protrusion 220 is adapted for contacting the electronic component to absorb heat therefrom. In the preferred embodiment of the present invention, the protrusion 220 is located at a front part of the panel 22; nevertheless, a location of the protrusion 220 on the panel 22 can be changed according to positions of the electronic component. Corresponding portions of the sidewalls 24 and the flanges 26 are bent outwardly and oppositely to form a pair of horizontal wings (not labeled) at two lateral sides of the lower plate 20, respectively. A pair of rectangular securing members 70 are disposed on the two wings of the lower plate 20 and inserted into the flanges 26 and the sidewalls 24, with an outer side thereof being coincidental with an outer edge of a corresponding wing. Each of the securing members 70 has a height larger than that of the sidewalls 24, whereby a top of the each securing member 70 extends beyond the flanges 26. A hole 700 is defined through each securing member 70 and each wing to provide a passage for a fastener (not shown).

The upper plate 30 is soldered on the two flanges 26 of the lower plate 20. The upper plate 30 has a periphery coincidental with a periphery of the lower plate 20. A pair of cutouts 32 are defined at each lateral side of the upper plate 30 corresponding to the wing, while a part of the upper plate 30 located between the pair of cutouts 32 forms a rectangular tab 34, which is for resiliently abutting against a corresponding securing member 70. Total areas of the two cutouts 32 and the tab 34 are identical to an area of a top face of the securing member 70 (illustrated in FIG. 1). A circular hole 340 is defined in each tab 34 corresponding to the hole 700 in the lower plate 20 and the securing member 70. The fastener extends through the circular hole 340 of the upper plate 30 and a corresponding hole 700 of the lower plate 20 and the securing member 70 to attach them on a printed circuit board (not shown) where the electronic component is mounted.

Also referring to FIG. 5, the upper fin set 40 and the lower fin set 50 are fixed on the upper plate 30 and the lower plate 20 by soldering, respectively. Each of the upper fin set 40 and the lower fin set 50 comprises a plurality of parallel fins 42, 52, each of which consists of an upright sheet (now labeled) and a pair of pieces (not labeled) bent horizontally from a top and a bottom of the sheet, respectively. The lower fin set 50 is secured on a rear part of the bottom face of the panel 22 and near the protrusion 220 (viewed from FIG. 4), by soldering upper pieces of the fins 52 on the panel 22; the upper fin set 40 is secured on a whole top face of the upper plate 30, by soldering lower pieces of the fins 42 on the upper plate 30, wherein every two adjacent fins 42, 52 form a passage therebetween for allowing an airflow therethrough. The lower fin set 50 has a width similar to that of the panel 22, and the upper fin set 40 has a profile coincidental to that of the upper plate 30 and a width larger than that of the lower fin set 50 (shown in FIG. 5).

As viewed from FIGS. 2-3, the heat pipes 60 are sandwiched between the upper plate 30 and the lower plate 20. In the preferred embodiment of the present invention there are four heat pipes 60; however, the number of the heat pipes 60 is adjustable according to amount of heat that the electronic component generates. Two middle ones 62 of the four heat pipes 60 are straight and planar and parallel to each other; two lateral ones 64 of the four heat pipes 60 are planar and each have a straight section 640 parallel to the two middle heat pipes 62, two bended sections 642 extending slantwise and outwardly from two opposite ends of the straight section 640, and an extremity end 644 extending backwardly from a rear bended section 642, wherein each bended section 642 defines an angle approximate to 135 degrees with the straight section 640. The four heat pipes 60 are so arranged that the two middle heat pipes 62 abut side-by-side against each other along a lengthwise direction of the lower plate 20, and the two lateral heat pipes 64 are juxtaposed with the two middle heat pipes 62 in a manner that the straight sections 640 thereof directly contact the two middle heat pipes 62, the bended sections 642 are inclinedly spaced from the two middle heat pipes 62, and the extremity ends 644 are gapped from and parallel to the two middle heat pipes 62. A distance from an outmost portion of a front bended section 642 to an outmost portion of the extremity end 644 of each lateral heat pipe 64 is identical to a length of the middle heat pipe 62. A distance between two extremity ends 644 of the two lateral heat pipes 64 is less than that between two sidewalls 24 of the lower plate 20, whereby when the four heat pipes 60 are fixed on the lower plate 20, the extremity ends 644 would be spaced from the sidewalls 24 to define gaps (not labeled) therebetween (illustrated in FIG. 5), which allow the airflow therethrough to increase heat dissipation of the heat sink 10. Each heat pipe 60 has a part projecting downwardly from a bottom face thereof to form a rectangular chassis 626, 646, which has a length less than that of the cavity 222 of the lower plate 20, and a thickness approximate to a depth of the cavity 222 of the lower plate 20. Four chassises 626, 646 are located just above the cavity 222 and for being substantially accommodated into the cavity 222 and directly contacting a top face of the protrusion 220 to absorb heat therefrom.

In use, the heat sink 10 is disposed on the printed circuit board with its protrusion 220 contacting with the electronic component, wherein the upper fin set 40 is located above the printed circuit board, and the lower fin set 50 extends downwardly beyond the printed circuit board and has a part located lower than the printed circuit board. Heat generated by the electronic component is absorbed by the protrusion 220, and then is transferred to other portions of the heat pipes 60 via the chassises 626, 646. The heat pipes 60 distribute the heat over the upper plate 30 and the lower plate 20, which disperses the heat to the ambient via the lower fin set 50 and the upper fin set 40.

In contrast to the conventional heat sink which forms grooves in a base to accommodate heat pipes therein, the lower plate 20 of the present invention does not need forming any grooves since the heat pipes 60 are sandwiched between the lower plate 20 and the upper plate 30 and directly welded on the lower plate 20, whereby no machine work is needed and a thickness of the lower plate 20 is capable of being controlled in a small range; thus, a machine cost and material cost of the heat sink 10 is reduced.

It is believed that the present invention and its advantages will be understood from the foregoing description, and it will be apparent that various changes may be made thereto without departing from the spirit and scope of the invention or sacrificing all of its material advantages, the examples hereinbefore described merely being preferred or exemplary embodiments of the invention. 

1. A heat sink adapted for cooling an electronic component, comprising: a lower plate; a lower fin set attached on a bottom face of the lower plate; an upper plate; an upper fin set attached on a top face of the upper plate; and a plurality of heat pipes sandwiched between the lower plate and the upper plate.
 2. The heat sink as claimed in claim 1, wherein the upper plate is planar, and the lower plate comprises a planar panel, the heat pipes being sandwiched between the upper plate and the panel.
 3. The heat sink as claimed in claim 2, wherein the lower plate further comprises a pair of sidewalls extending upwardly from two opposite lateral sides of the panel, and a pair of flanges extending horizontally from tops of the pair of sidewalls respectively and are soldered on the upper plate.
 4. The heat sink as claimed in claim 2 further comprising a pair of securing members inserted into the pair of sidewalls and the pair of flanges, wherein each of the pair of securing members has a rectangular configuration.
 5. The heat sink as claimed in claim 4, wherein the upper plate defines four cutouts at two lateral sides thereof and forms a pair of tabs between adjacent cutouts corresponding to the pair of securing members, the pair of tabs resiliently abutting against the securing members, respectively.
 6. The heat sink as claimed in claim 3, wherein the heat pipes are juxtaposed with each other and spaced from the pair of sidewalls of the lower plate to form air passages.
 7. The heat sink as claimed in claim 2, wherein the panel of the lower plate forms a protrusion projecting downwardly therefrom, and a cavity defined in the protrusion and opened upwardly.
 8. The heat sink as claimed in claim 7, wherein the upper fin set occupies a total area of a top face of the upper plate, and the lower fin set occupies a part of a bottom face of the panel and is located near the protrusion.
 9. The heat sink as claimed in claim 7, wherein corresponding parts of the heat pipes project downwardly to form chassises, the chassises being received in the cavity and contacting the protrusion directly.
 10. The heat sink as claimed in claim 1, wherein two middle ones of the heat pipes are straight, and two lateral ones of the heat pipes are partially bended and each has a straight section, a pair of bended sections extending slantwise from the straight section and an extremity end extending from one of the pair of bended sections.
 11. The heat sink as claimed in claim 10, wherein the two middle heat pipes and the straight sections of the two lateral heat pipes contact with each other, the bended sections are slantwise spaced from the two middle heat pipes, and the extremity ends are spaced from and parallel to the two middle heat pipes.
 12. A heat sink for dissipating heat from an electronic component, comprising: a lower plate comprising a planar panel; a planar upper plate; and a plurality of heat pipes substantially sandwiched between the panel and the upper plate; wherein the heat pipes are straight and juxtaposed with each other and directly contact with each other at a first position, and are at least partially separated from each other at a second position and a third position, the first position is located between the second position and the third position.
 13. The heat sink as claimed in claim 12, wherein the first position is located at a central area of the heat pipes, the second position and the third position are located at two opposite ends of the heat pipes, respectively.
 14. The heat sink as claimed in claim 12, wherein two middle ones of the heat pipes are straight and parallel to and directly contact with each other from begin to end.
 15. The heat sink as claimed in claim 14, wherein two lateral ones of the heat pipes each have a middle section being straight, two bended sections extending slantwise and outwardly from two opposite ends of the middle section, and an extremity end extending parallel to the middle section from one of the two bended sections.
 16. The heat sink as claimed in claim 15, wherein the middle sections of the two lateral heat pipes contact with the two middle heat pipes at the first position, corresponding bended sections are separated from the two middle heat pipes at the second position, and the extremity ends are separated from the two middle heat pipes at the third position.
 17. The heat sink as claimed in claim 12 further comprising an upper fin set arranged on the upper plate and a lower fin set arranged on the panel, wherein the upper fin set is located over the first position, the second position and the third position, and the lower fin set is located next to the third position.
 18. The heat sink as claimed in claim 12, wherein the panel has a protrusion formed downwardly therefrom and a cavity defined in the protrusion and opened upwardly, the protrusion being located adjacent to the second position.
 19. The heat sink as claimed in claim 18, wherein the heat pipes forms chassises on bottom faces thereof, the chassises being received in the cavity and contact the protrusion directly.
 20. The heat sink as claimed in claim 12, wherein the lower plate further comprises a pair of sidewalls extending upwardly from two lateral sides of the panel and two flanges extending horizontally and oppositely from tops of the pair of sidewalls, the pair of sidewalls being separated from the heat pipes and the two flanges are fixed on the upper plate. 